Segments - Reconciliation of Adjusted EBITDA to Net Income (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Jul. 31, 2016	Jul. 31, 2015	Apr. 30, 2016
Reconciliation of Adjusted EBITDA to Net income
Interest expense	$ (13,003)	$ (9,257)
Interest income	43	230
Income tax expense	(6,159)	(2,855)
Depreciation expense	(6,382)	(7,273)
Amortization expense	(9,413)	(8,792)
Stock appreciation rights expense	92	(594)
Redeemable noncontrolling interests	(292)	(554)
Equity-based compensation	(673)	(498)
Gain on disposal of assets	198	25
Management fee to related party	(188)	(562)
Net income	9,163	3,011	$ 12,564
Operating Segment
Reconciliation of Adjusted EBITDA to Net income
Adjusted EBITDA	45,941	34,113
Reconciling items
Reconciliation of Adjusted EBITDA to Net income
Severance and other permitted costs	(140)	(557)
Transaction costs (acquisitions and other)	(654)	$ (415)
Effects of fair value adjustments to inventory	(164)
Interest rate cap mark-to-market	$ (43)